The Sparta hit underwater ice Dec. 16 that tore a 1-foot (30-centimeter) hole in its hull, and heavy ice in the Ross Sea prevented help from arriving until Monday.

Before the South Korean icebreaker Araon arrived, the Sparta’s crew had been desperately pumping out near-frozen sea water and some had boarded life rafts.

New Zealand’s Rescue Coordination Center said good progress was made on internal repairs but the external damage could not be repaired for safety reasons. The work still is expected to make the Sparta seaworthy, and both ships are expected to leave the area Wednesday.

The Araon, a polar research ship, then is expected to escort the Sparta to ice-free open ocean, the center said in a statement Tuesday afternoon.